Compressor



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COMPRESSOR Filed June 9, 19%@ Patented @ctn 233,. w23.

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EDWIN c. BEAM, or NEWARK, NEW JERSEY, assIGNoR To Moron sran'ran a nrmrr CQMPANY.

COMPRESSOR.

Application le Tune 9, 1920. Serial No. 3872552.

To @ZZ whom t may cfm/cem.'

Be it known that I, EDWIN C; BAM, ren

siding at 706 Summer Avenue, Newark, in the county of Essex, State ofNew Jersey, have invented certain new and useful Improvements inCompressors; and 1 do hereby declare the following to be a full, clear,and exact description of the invention, such as will enable othersskilled in the art to which it appertains to make and use the same.

This invention relates to compressors, particularly adapted to compressair for use in automobile tires and the like, although the compressormay be employed for other purposes.

Air compressors are employed at automobile service stations to filltires or to maintain a supply of air under pressure in tanks, rom whichit is withdrawn as required. Such compressors are subjected to rough andcontinual usage under conditions which rapidly deteriorate compressorsof the type heretofore commonly used. Such compressors are not welladapted to use at service stations, and are particularly ineiicient inthe smaller sizes which are operated by driving mechanism worked at arelatively high speed.

Owing to the high speed at which the compressor is operated, it isessential to provide proper lubrication of the moving parts, and thisresult is best accomplished by enclosing such parts in a suitablecasing' and by entirely or partially filling the casing with oil.Automobile tires are rapidly disintegrated by oil and it is necessary,therefore, to prevent the lubricating oil from entering the compressioncylinder, from whichit may be carried over by the compressed air intothe tire.- lt is also desirable to secure the highest eiiciency -in ihecompressor and, at the same time to simplify the mechanism to a pointwhich insures continuous and extended service without attention.

It is the object of the present invention to provide a compact andefficient compressor of simple construction, with the working partsenclosed and operating in a bath of oil and at the same time to preventaccess of the oil to the compression cylindel.

llt vis a further object of the invention to provide an outlet for thecompressed air, which insures rapid and complete delivery of the airfrom the cylinder, and to so arrange the parts-that a minimum ofclearance between the piston and theend of the cylinder is permitted atthe end of the compression stroke.

Another object of the invention is to permit the ingress of air to thecylinder and to cushion the piston near the end `of the return strokewithout introducing suiiicient resistan e to prevent proper operation.

These and other objects and advantages of the invention will beunderstood, upon reference to the following specication and to theaccompanying drawings of which;

Fig. 1 is a vertical section throughthe compressor constructed inaccordance with the invention; and

Fig. 2 is a section on line 2 2 of F ig. 1.

Referring to the drawing, 5 indicates a casing which may be of anysuitable form and dimensions to enclose the operating mefhanism of thecompressor, which includes a shaft 6 driven through a gear 7 from asource of power and having a crank 8 which is connected by link 9 to arocker 1G, pivoted at 11 within the casing. A piston rod 12 is pivotallyconnected at 13 to the rocker 10. A cylinder 14 is supported on thecasing 5 and a piston 15 is disposed therein and provided with suitablepiston rings 16 to insure close fit between the piston and the cylinder.The piston 15 is rovided with a recess to receive a bal 1 7 on the endof the piston rod 12. The connection between the piston rod 12 andpiston15 is maintained by an annulus 18, threadedly secured in the recess,which prevents the ball 17 from escaping therefrom. A Cotter pin 19secures the annulus in place.

The cylinder 14 is provided with ports 20 permitting ent-rance of airabove the piston 15 when the latter is at its lowest position, and ashield 21 surrounding the cylinder in front of the ports 20, preventstheentrance of dust or other foreign matter to the cylinder. The shield21 acts as a bathe and provides the air space 22 to which air isadmitted through the annular opening 23 at its base. lt is preferably suported on a flange 24 surrounding the cylin er. At

a head 25 having an outlet 26, which is closed during the return strokeof the piston by disk valve 27 resting upon a lip 28. A plug 29 threadedin the head 25 is provided with a lip 30, which limits upward movementof the valve 27. The head 25 has an annular space 31, surrounding thevalve 27, to which compressed air passing the valve is admitted by aseries of inlets 32, when the valve is lifted from the lip 28. Thisarrangement insures the free passage of compressed air from the cylinderupon the compression stroke and increases the eiciency and reduces thepower consumption of the compressor. From the chamber 31,'the air ispermitted to escape through a pipe 33 which is threadedly connected tothe head '25 at 34.

Upon the compression stroke of the piston 15 the air, which has enteredthrough the ports 20, is compressed and when the depending flange 35 onthe piston 15 passes these ports, air is admitted through the openingsat the rear of the piston to prevent drawing a partial vacuum behind thepiston. Upon the return stroke a portion of this air is trapped behindthe piston as the lower edge of the ange againpasses the ports 20. andserves to cushion the return stroke of the piston. Unless provision ismade to permit escape ot this air, it will cause too much resistance tothe operation vof the compressor, and accordingly a vent 36 isprovided'near the base of the cylinder 14 to permit the escape of theair. `The vent is so proportioned that the desired cushion effect ispreserved, without interfering with the operation of the compressor.

As previouslynoted, the casing `5 is filled or partially filled with alubricator, such as oil, and unless prevented the oil will escapeintothe cylinder and will eventually work its way past the piston,thereby permitting the compressed Iair to carry oil to the storage tank'or tire. An annular washer 37 is therefore provided in the cylinder 14Cabove the casing 5 and a washer 38 is supported on the piston rod,between the washer 37 and the topof the casing 5. The washer 38 closesthe opening 41 in the top of the casing 5 in which the piston rodtravels and efectua'flly prevents the escape of oil from the casina 5.Preferably the washer 38 is providedb with a'flange 39 having aspherical surface, which co-operates with a ball 40' having an openingthrough which the piston rod is adapted to slide, the flange and ball'constituting a ball and socket connection between the washer and thepiston rod. rIhus the washer 38 travels in a plane between the top' oithe casing 5 and. the washer 37 as the piston rod reciprocates andswings under the actuation of the rocker 10. lt is impossible thereforefor oil to pass the provided, which has obvious advantages over -1compressors of the usual type heretofore cmployed for purposes towhichgthe present structure is adapted. The stroke of the piston is morethan twice the diameter of the crank 'circle and the compressor may beoperated at high speed. A free inlet and outlet for the air is provided,which insures that the cylinder is fully evacuated at the end of thecompression stroke, and is again filled with air before the oommencementof the succeeding compression stroke. The entire compressor isself-contained and self-lubricated. The parts are protected from dirtand 'foreign matter, which would otherwise cause rapid wearing of thecontacting surfaces. The cushion effeet of the air trapped behind thepiston prevents jarring and consequent destruct-ion of the mechanism.The cylinder is fully protected against the entrance of lubricating oiland consequently the compressor may be safely used for compressing airwhich is subsequently `employed in filling automobile tires.

Various changes may be made in the form, arrangement, and constructionof the parts and in the dimensions as shown, without departing from theinvention or sacrificing any of its advantages. y

l cla-im:

1. In a compressor, the combination of a cylinder, a piston in thecylinder, Aa piston rod connected to the piston, operating mechanismtherefor. a casing for the mechanism, and adapted to contain alubricant, and means for preventing escape i of the lubricant includingan annular.l washer at the base of the cylinder, anda washer having aball and socket connection" with the piston rod and disposed between theannular washer and the top of the casing and of a diameter less thanthat of the annular washer thereby to slide freely in every di `rection,said washers being adapted to close the o ning in which the piston rodtravels.

2. n a compressor, the combination of a cylinder, a piston in thecylinder, ports for admitting air to the cylinder, the ports beingspaced away from the inner end of the cylinder, and the piston having anannular flange engaging the cylinder wall and of a length to cover andclose the ports before the piston reaches the end of its down stroke, I

thereby to trap a relatively large body of air to form a cushion betweenthe piston and the end of the cylinder, the cylinder having a restrictedoutlet for the trapped air.

3.. In a compressor, the combination of a cylinder, a piston in thecylinder, a rod conmated be the piston, operating mechanism therefor, acasi nda-pted to contaln a. lubricant, means for preventing escape ofthe lubricant includ- 5 in an annular washer at the base of the cyindex, and a, Washer through which the rod extends (iisposed between theannular Washer and the top of the msi, and of a,

for the meehanism and EDN Q, BE.,

